Take remote-chromium.sh's host as an argument instead of an env var

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -142,7 +142,8 @@ someone types the disk passphrase locally) unless something like
 
 ## Single remote app: Chromium with your logged-in accounts
 
-`remote-chromium.sh` (run on the travel laptop) closes any Chromium you have
+`remote-chromium.sh [--x11] [host]` (run on the travel laptop; host defaults to
+`teemu-thinkpad-ubuntu`) closes any Chromium you have
 running on the home machine, then launches it there with its window drawn
 locally via `waypipe` (`--x11` for classic X11 forwarding instead). The close
 step matters: Chromium allows one process per profile, so a still-running

remote-chromium.sh

@@ -4,13 +4,20 @@
 # would swallow the new window), then launches it there with its window
 # drawn here.
 #
-# Usage: remote-chromium.sh [--x11]     (default: waypipe)
-# Remote host: $REMOTE_HOST, default teemu-thinkpad-ubuntu
+# Usage: remote-chromium.sh [--x11] [host]
+#   --x11   classic X11 forwarding instead of waypipe
+#   host    ssh host to run Chromium on (default: teemu-thinkpad-ubuntu)
 set -euo pipefail
 
-HOST="${REMOTE_HOST:-teemu-thinkpad-ubuntu}"
 MODE="waypipe"
-[ "${1:-}" = "--x11" ] && MODE="x11"
+HOST="teemu-thinkpad-ubuntu"
+for arg in "$@"; do
+  case "$arg" in
+    --x11) MODE="x11" ;;
+    -*)    echo "Unknown option: $arg"; exit 1 ;;
+    *)     HOST="$arg" ;;
+  esac
+done
 
 if [ "$MODE" = "waypipe" ] && ! command -v waypipe >/dev/null 2>&1; then
   echo "waypipe not installed here - run: sudo apt install waypipe (needed on both machines)"